Surface treatment composition for metal working

ABSTRACT

A surface treatment composition for metal working which comprises 20 to 50 parts by weight of a mixture of a chlorine-containing thermoplastic synthetic resin or chlorine-containing rubber having a molecular weight of 8000 to 10000 and a chlorine-containing thermoplastic synthetic resin or chlorine-containing rubber having a molecular weight of 17000 to 19000, 2 to 15 parts by weight of a plasticizer and 2 to 20 parts by weight of a wax having 30 to 80 carbon atoms and melting at 60° to 120°C.

The present invention relates to a surface treatment composition formetal working. More particularly, it relates to a lubricatingcomposition for surface treatment for metal working which can be appliedon the surface of metals prior to the plastic deformation of them andcan facilitate the plastic deformation.

In cold molding of metals such as transformation processing, drawingprocessing and deep drawing processing, the surface of metals to beprocessed is usually coated with a treating agent such as lubricatingoil, wax, molybdenum or soap prior to the processing. Particularly incase that such processing is difficult, the surface of metals isgenerally subjected to chemical treatment with a phosphate, an oxalateor the like prior to the above mentioned coating. However, suchconventional surface treatment of metals is disadvantageous in variousrespects: e.g. (1) the strict control of the reaction is necessitated inthe chemical treatment; (2) heating is required in the chemicaltreatment; (3) sludge is formed during the reaction; (4) the treatmentof the waste reaction solution makes much troubles; (5) the number ofthe operation steps is much; (6) such surface treatment is notapplicable to a highly advanced processing procedure, for instance,under an increased drawing rate or speed or reduction rate, etc.

There is also known a process of coating with a highly chlorinatedhigher fatty acid. However, the obtained coating film is not dried norsolidified completely but remains adhesive, so that, in the processingoperation, a part of the treating agent hangs down from the metal tomake the coating film non uniform and, in extreme cases, renders theoperation environment sticky and also handling of the metal verydifficult.

The main object of the present invention is to provide a treating agentfor surface treatment advantageously utilizable for processing ofmetals. Another object of this invention is to provide a treating agentfor surface treatment which can effectively coat the surface of metalsat room temperature without any chemical reaction, which means thatthere is no necessity for treating the sludge or the waste ordinarilyformed during the reaction. A further object of the invention is toprovide a treating agent for surface treatment which requires fewersteps of operation and affords a uniform coating film which issufficiently dried and which exhibits good work-ability and lubricity.

The composition of the treating agent of the invention comprises 20 to50 parts by weight of a mixture of a thermoplastic synthetic resincontaining chlorine or a chlorine-containing rubber, having a molecularweight of 8000 to 10000, and a thermoplastic synthetic resin containingchlorine or a chlorine-containing rubber, having a molecular weight of17000 to 19000, 2 to 15 parts by weight of a plasticizer and 2 to 20parts by weight of a wax having 30 to 80 carbon atoms and melting at 60°to 120°C.

The thermoplastic synthetic resin containing chlorine and thechlorine-containing rubber used herein may be conventional ones.Specific examples of them are chlorinated polyethylene, chlorinatedpolypropylene, polyvinyl chloride, polyvinylidene chloride andchlorinated natural rubber. Among them, the use of the ones having achlorination rate of 60 % or more is favorable. It is indispensable forthe composition of the invention to contain a thermoplastic syntheticresin containing chlorine or the chlorine-containing rubber, having amolecular weight of 8000 to 10000, and a thermoplastic synthetic resincontaining chlorine or a chlorine-containing rubber, having a molecularweight of 17000 to 19000, in combination. Particularly by the combineduse of the chlorine-containing rubber having a molecular weight of 8000to 10000 and the chlorine-containing rubber having a molecular weight of17000 to 19000, there can be expected further improvement in alubricating property. When the thermoplastic synthetic resins containingchlorine and/or chlorine-containing rubbers, having a molecular weightof 17000 to 19000, are employed solely or in combination, the adhesionof the formed coating film on the surface of the substrate metal becomesinferior. When thermoplastic synthetic resins containing chlorine and/orchlorine-containing rubbers, having a molecular weight of 8000 to 10000,are employed solely or in combination, the adhesion of the formedcoating film on the surface of the substrate metal is good, but thelubricity becomes insufficient.

The mixing proportion of the compound having a molecular weight of 17000to 19000 and the compound having a molecular weight of 8000 to 10000 isdesired to be 1 : 1.2 to 1.8 by weight. When the proportions are out ofthis range, there are caused the above mentioned drawbacks as seen incase of the sole use of the compound having a molecular weight of 17000to 19000 or the compound having a molecular weight of 8000 to 10000.

As the plasticizer, there may be employed a phthalic acid ester, anadipic acid ester, an alkylphosphoric acid ester, a chlorinated paraffinor the like. The use of chlorinated paraffin, especially having achlorination rate of 40 to 80 % and a molecular weight of 1000 or more,is preferable.

As the wax, there may be employed animal wax, vegetable wax, petroleumparaffin wax, petrolatum, fine crystalline wax or the like. The use of awax material having 30 to 80 carbon atoms (preferably 40 to 60 carbonatoms) and a melting point of 60° to 120°C (preferably 70° to 90°C) isfavorable. Particularly preferred is a wax containing a side chain and aring in its molecule and having a fine crystalline structure (i.e.microcrystalline wax). For further improving the lubricating property,the use of microcrystalline wax of plastic type having a melting pointof 79° to 80°C is desired. The use of an oil or a fat such as Vaseline,a low molecular weight paraffin or a mineral oil in place of the wax isnot favorable, because the formed coating film is very soft and weak andis not able to be sufficiently dried to that its handling becomesdifficult. Further, due to its insufficient lubricity, the film is aptto be directly contacted with metal tools at the plastic deformationoperation, which results in the formation of die marks on its surface.

In addition to the above mentioned components, the composition of theinvention may contain any other conventional additives such as soaps,pigments, dyestuffs, anti-corrosion agents and perfumeries. As the soapsto be incorporated in the composition of the invention, metal salts(e.g. Na, K, Li, Ca, Al, Zn, Pb) of higher fatty acids having 8 to 22carbon atoms are favorable.

In the composition of the invention, there may be also incorporated oneor more kinds of solvents such as alcohols (e.g. ethanol, isopropanol,butanol), esters (e.g. ethyl acetate, butyl acetate, amyl acetate),ethers (e.g. butyl cellosolve, carbitol), ketones (e.g. methyl ethylketone, methyl isobutyl ketone), hydrocarbons (e.g. mineral spirit,toluene, xylene, solvent naphtha) and halogenated hydrocarbons (e.g.trichloroethylene, perchloroethylene). The kind of the solvent to beused should be appropriately selected depending on the boiling point,the dissolving ability, the ignition point and the like. The amount ofthe solvent to be used is usually 1 to 60 % by weight, preferably 10 to40 % by weight, to the solid content of the composition. When a heavycoating film, e.g. having a weight of 5 g/m² or more, is desired, it isfavorable to use the solvent in such an amount that the solid content ofthe composition becomes 10 % by weight or more.

The composition of the invention can be applied on the surface of ametal substrate by a conventional procedure such as immersion, flowcoating, spraying or roll coating.

The coating film prepared from the composition of the invention iscompletely dried and not sticky at all so that the coated metal can behandled with ease without sticking. Further, the coating film of theinvention has a uniform thickness and a flat and smooth surface andshows good processability with lubricity. In addition, by the use of thecomposition of the invention, highly advanced drawing processing ofstainless steel tubes can be effected with shortened operation steps andrepetition of the treatment for the processing at every drawingoperation is not required thereby, as shown in the hereinafter mentionedExample 5, unlike conventional procedures.

Thus, the composition of the invention can be advantageously employed intransformation processing, especially in drawing processing.

The practical and presently preferred embodiments of the invention areillustratively shown in the following Examples wherein parts and % areby weight.

EXAMPLE 1

    Composition 1                                                                 Chlorinated polypropylene                                                                             1.25     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      0.83     part                                         (molecular weight, about 18000)                                               Chlorinated paraffin    0.83     part                                         (chlorination rate, 70 %)                                                     Microcrystalline wax    5.00     parts                                        (before purification)                                                         Calcium stearate        10.00    parts                                        Bentonite               0.09     part                                         3,4-Epoxycyclohexylmethyl-3,4-epoxy-                                                                  0.04     part                                         cycolhexanecarboxylate                                                        Toluene                 3.72     parts                                        Perchloroethylene       78.24    parts                                                                100.00   parts                                        Composition 2                                                                 Chlorinated polypropylene                                                                             1.25     parts                                        (molecular weight, about 9000)                                                Chlorinated polypropylene                                                                             0.83     part                                         (molecular weight, about 18000)                                               Chlorinated paraffin    0.83     part                                         (chlorination rate, 70 %)                                                     Microcrystalline wax    5.00     parts                                        (before purification)                                                         Calcium stearate        10.00    parts                                        Bentonite               0.09     part                                         3,4-Epoxycyclohexylmethyl-3,4-epoxy-                                                                  0.04     part                                         cyclohexanecarboxylate                                                        Toluene                 3.72     parts                                        Perchloroethylene       78.24    parts                                                                100.00   parts                                        Composition 3                                                                 Chlorinated rubber      1.25     parts                                        (molecular weight, about 9000)                                                Chlorinated polypropylene                                                                             0.83     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    0.83     part                                         (chlorination rate, 70 %)                                                     Microcrystalline wax    5.00     parts                                        (before purification)                                                         Calcium stearate        10.00    parts                                        Bentonite               0.09     part                                         3,4-Epoxycyclohexylmethyl-3,4-epoxy-                                                                  0.04     part                                         cyclohexanecarboxylate                                                        Toluene                 3.72     parts                                        Perchloroethylene       78.24    parts                                                                100.00   parts                                        Composition 4                                                                 Chlorinated rubber      1.25     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      0.83     part                                         (molecular weight, about 18000)                                               Chlorinated paraffin    0.83     part                                         (chlorination rate, 70 %)                                                     Microcrystalline wax    5.00     parts                                        (before purification)                                                         Calcium stearate        10.00    parts                                        Bentonite               0.09     part                                         3,4-Epoxycyclohexylmethyl-3,4-epoxy-                                                                  0.04     part                                         cyclohexanecarboxylate                                                        Toluene                 3.72     parts                                        Perchloroethylene       78.24    parts                                                                100.00   parts                                        Composition 5                                                                 Chlorinated polypropylene                                                                             1.25     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      0.83     part                                         (molecular weight, about 18000)                                               Chlorinated paraffin    0.83     part                                         (chlorination rate, 70 %)                                                     Microcrystalline wax    5.00     parts                                        (plastic type)                                                                Calcium stearate        10.00    parts                                        Bentonite               0.09     part                                         3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.04     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 3.72     parts                                        Perchloroethylene       78.24    parts                                                                100.00   parts                                        Composition 6                                                                 Chlorinated polypropylene                                                                             1.25     parts                                        (molecular weight, about 9000)                                                Chlorinated polypropylene                                                                             0.83     part                                         (molecular weight, about 18000)                                               Chlorinated paraffin    0.83     part                                         (chlorination rate, 70 %)                                                     Microcrystalline wax    5.00     parts                                        (plastic type)                                                                Calcium stearate        10.00    parts                                        Bentonite               0.09     part                                         3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.04     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 3.72     parts                                        Perchloroethylene       78.24    parts                                                                100.00   parts                                        Composition 7                                                                 Chlorinated rubber      1.25     parts                                        (molecular weight, about 9000)                                                Chlorinated polypropylene                                                                             0.83     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    0.83     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    5.00     parts                                        (plastic type)                                                                Calcium stearate        10.00    parts                                        Bentonite               0.09     part                                         3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.04     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 3.72     parts                                        Perchloroethylene       78.24    parts                                                                100.00   parts                                        Composition 8                                                                 Chlorinated rubber      1.25     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      0.83     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    0.83     part                                         (chlorination rate, 70 %)                                                     Microcrystalline wax    5.00     parts                                        (plastic type)                                                                Calcium stearate        10.00    parts                                        Bentonite               0.09     part                                         3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.04     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 3.72     parts                                        Perchloroethylene       78.24    parts                                                                100.00   parts                                    

Each of the above compositions 1 to 8 (100 parts) is admixed withperchloroethylene (70 parts). In the obtained mixture, a steel panel (7cm × 15 cm) previously degreased with a weakly alkaline degreasing agentand washed is immersed at room temperature (about 20°C). After about 10seconds, the panel is taken out and dried at room temperature. In allcases, the coating film formed on the panel has a substantially eventhickness and is completely dried, not sticky, and flat and smooth, andany wave-like marks are not observed thereupon.

EXAMPLE 2

    Composition 9                                                                 Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    3.60     parts                                        (before purification)                                                         3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.22     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 23.89    parts                                        Perchloroethylene       48.50    parts                                                                100.00   parts                                        Composition 10                                                                Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated polypropylene                                                                             5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    3.60     parts                                        (before purification)                                                         3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.22     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 23.89    parts                                        Perchloroethylene       48.50    parts                                                                100.00   parts                                        Composition 11                                                                Chlorinated rubber      8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated polypropylene                                                                             5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    3.60     parts                                        (before purification)                                                         3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.22     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 23.89    part                                         Perchloroethylene       48.50    parts                                                                100.00   parts                                        Composition 12                                                                Chlorinated rubber      8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    3.60     parts                                        (before purification)                                                         3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.22     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 23.89    parts                                        Perchloroethylene       48.50    parts                                                                100.00   parts                                        Composition 13                                                                Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.22     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 23.89    parts                                        Perchloroethylene       48.50    parts                                                                100.00   parts                                        Composition 14                                                                Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, 9000)                                                      Chlorinated polypropylene                                                                             5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.22     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 23.89    parts                                        Perchloroethylene       48.50    parts                                                                100.00   parts                                        Composition 15                                                                Chlorinated rubber      8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated polypropylene                                                                             5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.22     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 23.89    parts                                        Perchloroethylene       48.50    parts                                                                100.00   parts                                        Composition 16                                                                Chlorinated rubber      8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                3,4-Epoxycyclohexylmethyl-3,4-                                                                        0.22     part                                         epoxycyclohexanecarboxylate                                                   Toluene                 23.89    parts                                        Perchloroethylene       48.50    parts                                                                100.00   parts                                    

Each of the above compositions 9 to 16 (100 parts) is admixed withperchloroethylene (100 parts). Using the obtained mixture, the formationof a coating film on a steel panel is carried out as in Example 1. Inall cases, the formed coating film has a substantially even thicknessand is completely dried, not sticky, and flat and smooth, and anywave-like marks are not observed thereupon.

EXAMPLE 3

    Composition 17                                                                Chlorinated polypropylene                                                                             31.25    parts                                        (molecular weight, about 9000)                                                Chlorinated paraffin    31.25    parts                                        (chlorination rate, 70 %)                                                     "Chissonox"             1.25     parts                                        (stabilizer for resins)                                                       Toluene                 13.59    parts                                        Perchloroethylene       22.66    parts                                                                100.00   parts                                        Composition 18                                                                Chlorinated rubber      15.20    parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    15.20    parts                                        (chlorination rate, 70 %)                                                     "Chissonox"             0.61     part                                         Toluene                 25.87    parts                                        Perchloroethylene       43.12    parts                                                                100.00   parts                                        Composition 19                                                                Chlorinated polypropylene                                                                             18.75    parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      12.50    parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    12.50    parts                                        (chlorination rate, 70 %)                                                     "Chissonox"             0.50     part                                         Toluene                 20.91    parts                                        Perchloroethylene       34.84    parts                                                                100.00   parts                                        Composition 20                                                                Chlorinated rubber      12.50    parts                                        (molecular weight, about 18000)                                               Chlorinated rubber      18.75    parts                                        (molecular weight, about 9000)                                                Chlorinated paraffin    12.50    parts                                        (chlorination rate, 70 %)                                                     "Chissonox"             0.50     parts                                        Toluene                 20.91    parts                                        Perchloroethylene       34.84    parts                                                                100.00   parts                                    

Each of the above compositions 17 to 20 (100 parts) is admixed withperchloroethylene (100 parts). Using the obtained mixture, the formationof a coating film on a stainless steel tube is carried out as inExample 1. The formed coating film is subjected to processing under thefollowing conditions:

Material: stainless steel tube (SUS-27) (outer diameter, 35.0 mm;thickness, 3.0 mm)

Drawing speed: 20 m/min

Processing method: so

1. Floating plug method

2. Bar drawing method

In case of the floating plug method, the procedure is repeated twicecontinuously, and in case of the bar drawing method, the procedure isrepeated three times continuously. Recoating and annealing at everyprocessing operation are not executed.

The results are shown in Table 1 in which the symbols have the followingmeanings, respectively:

: The drawing processing is normally effected.

Δ : A small amount of wave-like dies marks are observed on the surfaceof the steel tube.

x : The lubricity is insufficient, and a large amount of wave-like diesmarks are observed on the surface of the steel tube, or the tube isbroken.

-- : The drawing cannot be executed.

The stabilizer for resins "Chissonox" as used in Example 3 is3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate.

                  Table 1                                                         ______________________________________                                        Results                                                                       Procedure    Floating     Bar drawing                                                      plug method  method                                              ______________________________________                                        Number of times                                                                            1       2        1     2     3                                   of drawing                                                                    Size (mm)    35.0    29.0     35.0  33.0  31.0                                             × ×  ×                                                                             ×                                                                             ×                                          3.00    2.25     3.0   2.5   2.0                                              ↓                                                                              ↓ ↓                                                                            ↓                                                                            ↓                                         29.0    24.0     33.0  31.0  29.0                                             × ×  ×                                                                             ×                                                                             ×                                          2.25    1.75     2.5   2.0   1.5                                 Reduction rate (%)                                                                         37.3    22.1     20.6  19.0  17.4                                 Composition                                                                           17      x       --     x     --    --                                No.      18      x       --     x     --    --                                         19      x       --     Δ                                                                             x     --                                         20      Δ x            x     --                                ______________________________________                                    

From Table 1, it is apparent that the composition not containing the waxof the invention affords a coating film being inferior inprocessability.

EXAMPLE 4

    Composition 21                                                                Chlorinated polypropylenes                                                                            16.45    parts                                        (molecular weight, about 9000)                                                Microcrystalline wax    10.53    parts                                        (plastic type)                                                                "Chissonox"             0.66     part                                         Toluene                 27.14    parts                                        Perchloroethylene       45.22    parts                                                                100.00   parts                                        Composition 22                                                                Chlorinated rubber      16.45    parts                                        (molecular weight, about 18000)                                               Microcrystalline wax    10.53    parts                                        (plastic type)                                                                "Chissonox"             0.66     part                                         Toluene                 27.14    parts                                        Perchloroethylene       45.22    parts                                                                100.00   parts                                        Composition 23                                                                Chlorinated polypropylene                                                                             9.87     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      6.58     parts                                        (molecular weight, about 18000)                                               Microcrystalline wax    10.53    parts                                        (plastic type)                                                                "Chissonox"             0.26     part                                         Toluene                 27.29    parts                                        Perchloroethylene       45.47    parts                                                                100.00   parts                                        Composition 24                                                                Chlorinated rubber      9.87     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      6.58     parts                                        (molecular weight, about 18000)                                               Microcrystalline wax    10.53    parts                                        (plastic type)                                                                "Chissonox"             0.26     parts                                        Perchloroethylene       45.47    parts                                                                100.00   parts                                        Composition 25                                                                Chlorinated polypropylene                                                                             13.42    parts                                        (molecular weight, about 9000)                                                Chlorinated paraffin    13.42    parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                "Chissonox"             0.54     part                                         Toluene                 24.01    parts                                        Perchloroethylene       40.01    parts                                                                100.00   parts                                        Composition 26                                                                Chlorinated rubber      13.42    parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    13.42    parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                "Chissonox"             0.54     parts                                        Toluene                 24.01    parts                                        Perchloroethylene       40.01    parts                                                                100.00   parts                                    

Each of the above compositions 21 to 26 (100 parts) is admixed withperchloroethylene (100 parts). Using the obtained mixture, the formationof a coating film on a stainless steel tube is carried out as inExample 1. The formed coating film is subjected to processing as inExample 3.

The results are shown in Table 2.

                  Table 2                                                         ______________________________________                                        Results                                                                       Procedure    Floating     Bar drawing                                                      plug method  method                                              ______________________________________                                        Number of times                                                                            1       2        1     2     3                                   of drawing                                                                    Size (mm)    35.0    29.0     35.0  33.0  31.0                                             × ×  ×                                                                             ×                                                                             ×                                          3.00    2.25     3.0   2.5   2.0                                              ↓                                                                              ↓ ↓                                                                            ↓                                                                            ↓                                         29.0    24.0     33.0  31.0  29.0                                             × ×  ×                                                                             ×                                                                             ×                                          2.25    1.75     2.5   2.0   1.5                                 Reduction rate (%)                                                                         37.3    22.1     20.6  19.0  17.4                                 Composition                                                                           21      x       x            x     --                                No.      22      x       x            x     --                                         23              x                  Δ                                    24                                 x                                          25              x                  x                                          26              x                  x                                 ______________________________________                                    

It is apparent from Table 2 that when the plasticizer of the inventionis not used or the compound having a molecular weight of 8000 to 10000or the compound having a molecular weight of 17000 to 19000 is employedsolely, the obtained coating film becomes inferior in processibility.

EXAMPLE 5

    Composition 27                                                                Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Microcrystalline wax    3.80     parts                                        (plastic type)                                                                "Chissonox"             0.22     part                                         Toluene                 28.95    parts                                        Perchloroethylene       48.24    parts                                                                100.00   parts                                        Composition 28                                                                Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                "Chissonox"             0.22     part                                         Toluene                 27.15    parts                                        Perchloroethylene       45.24    parts                                                                100.00   parts                                        Composition 29                                                                Chlorinated polypropylene                                                                             8.60     parts                                        (molecular weight, about 18000)                                               Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                "Chissonox"             0.22     part                                         Toluene                 27.15    parts                                        Perchloroethylene       45.24    parts                                                                100.00   parts                                        Composition 30                                                                Chlorinated rubber      8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                "Chissonox"             0.22     part                                         Toluene                 27.15    parts                                        Perchloroethylene       45.24    parts                                                                100.00   parts                                        Composition 31                                                                Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (before purification)                                                         "Chissonox"             0.22     part                                         Toluene                 27.15    parts                                        Perchloroethylene       45.24    parts                                                                100.00   parts                                        Composition 32                                                                Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (hard type)                                                                   "Chissonox"             0.22     part                                         Toluene                 27.15    parts                                        Perchloroethylene       45.24    parts                                                                100.00   parts                                        Composition 33                                                                Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    11.41    parts                                        (plastic type)                                                                "Chissonox"             0.22     parts                                        Toluene                 26.09    parts                                        Perchloroethylene       43.49    parts                                                                100.00   parts                                        Composition 34                                                                Chlorinated polypropylene                                                                             3.60     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      2.40     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    2.40     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    25.00    parts                                        (plastic type)                                                                "Chissonox"             0.10     part                                         Toluene                 24.94    parts                                        Perchloroethylene       41.56    parts                                                                100.00   parts                                        Composition 35                                                                Chlorinated polypropylene                                                                             12.00    parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      8.00     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    8.00     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    1.00     part                                         (plastic type)                                                                "Chissonox"             0.32     part                                         Toluene                 26.51    parts                                        Perchloroethylene       44.17    parts                                                                100.00   parts                                    

Each of the above compositions 27 to 35 (100 parts) is admixed withperchloroethylene (100 parts). Using the obtained mixture, the formationof a coating film on a stainless steel tube is carried out as inExample 1. The formed coating film is subjected to processing as inExample 3.

CONTROL EXAMPLE

The formation of a coating film on a stainless steel tube is carried outby a conventional procedure comprising the oxalate treatment and thesoap treatment. The formed coating film is subjected to processing as inExample 3.

The results are shown in Table 3.

                  Table 3                                                         ______________________________________                                        Results                                                                       Procedure    Floating     Bar drawing                                                      plug method  method                                              ______________________________________                                        Number of times                                                                            1       2        1     2     3                                   of drawing                                                                    Size (mm)    35.0    29.0     35.0  33.0  31.0                                             × ×  ×                                                                             ×                                                                             ×                                          3.00    2.25     3.0   2.5   2.0                                              ↓                                                                              ↓ ↓                                                                            ↓                                                                            ↓                                         29.0    24.0     33.0  31.0  29.0                                             × ×  ×                                                                             ×                                                                             ×                                          2.25    1.75     2.5   2.0   1.5                                 Reduction rate (%)                                                                         37.3    22.1     20.6  19.0  17.4                                 Composition                                                                           27                                                                   No.      28                                                                            29                                                                            30                                                                            31              Δ                                                       32              Δ                                                       33                                                                            34              x                  x                                          35              x                  x                                  Control Example     x              x     --                                  ______________________________________                                    

As apparent from Table 3, the film prepared from the composition of theinvention (not including the compositions 34 and 35 in which the amountof the microcrystalline wax is out of the range of the invention) showsan excellent processability, compared with the film obtained by theconventional procedure comprising the oxalate treatment and the soaptreatment, and can be continuously subjected to the drawing processingwithout being recoated at every processing. The compositions 27, 28, 29,30 and 33 can afford good results in high reduction rate. Among them,the composition 30 comprising the chlorine-containing rubber having amolecular weight of about 9000 and the chlorine-containing rubber havinga molecular weight of about 18000 is particularly superior to the restsin smooth drawing state and in beautiful appearance of the drawn tube.It is confirmed from the results obtained in the cases of thecompositions 31 and 32 that the processability is varied depending onthe melting point of the wax (microcrystalline wax before purified,77°C; microcrystalline wax of hard type, 83° to 90°C; microcrystallinewax of plastic type, 79° to 82°C).

The lubricating effect of the composition of the invention is muchelevated by the incorporation of carbon fluoride therein usually in anamount of about 1 to 20 parts to 54 to 165 parts of the composition. Inthe case wherein the amount is less than the lower limit, a satisfactoryeffect cannot be obtained. In the case of the amount being more than theupper limit, the adhesion to the surface of the metal substrate becomesinferior and the multi-step processing is made difficult. The followingexample illustrates the effect of carbon fluoride:

EXAMPLE 6

    Composition 36                                                                Chlorinated polypropylene                                                                             8.05     parts                                        (molecular weight, about 9000)                                                Chlorinated rubber      5.37     parts                                        (molecular weight, about 18000)                                               Chlorinated paraffin    5.37     parts                                        (chlorination rate, 70 %)                                                     Microcrystalline wax    8.60     parts                                        (plastic type)                                                                Carbon fluoride         5.00     parts                                        "Chissonox"             0.22     part                                         Toluene                 27.15    parts                                        Perchloroethylene       40.24    parts                                                                100.00   parts                                    

The above composition 36 (100 parts) is admixed with perchloroethylene(100 parts). Using the obtained mixture, the formation of a coating filmon a stainless steel tube is carried out as in Example 1. The formedcoating film is subjected to processing as in Example 3.

The results are shown in Table 4.

                  Table 4                                                         ______________________________________                                        Results                                                                       Procedure     Floating    Bar drawing                                                       plug method method                                              ______________________________________                                        Number of times                                                                             1       2       1     2     3                                   of drawing                                                                    Size (mm)     35.0    29.0    35.0  33.0  31.0                                              × × ×                                                                             ×                                                                             ×                                           3.00    2.25    3.0   2.5   2.0                                               ↓                                                                              ↓                                                                              ↓                                                                            ↓                                                                            ↓                                          29.0    24.0    33.0  31.0  29.0                                              × × ×                                                                             ×                                                                             ×                                           2.25    1.75    2.5   2.0   1.5                                 Reduction rate (%)                                                                          37.3    22.1    20.6  19.0  17.4                                Composition No. 36                                                            ______________________________________                                    

What is claimed is:
 1. A surface treatment composition for metal workingwhich comprises 20 to 50 parts by weight of (A) a mixture of (A-1) achlorine-containing thermoplastic synthetic resin or chlorine-containingrubber having a molecular weight of 8000 to 10,000, which resin andrubber materials are selected from the group consisting of chlorinatedpolyethylene, chlorinated polypropylene, polyvinyl chloride,polyvinylidene chloride and chlorinated natural rubber and (A-2) achlorine-containing thermoplastic synthetic resin or chlorine-containingrubber having a molecular weight of 17,000 to 19,000, which resin orrubber materials are selected from the group consisting of chlorinatedpolyethylene, chlorinated polypropylene, polyvinyl chloride,polyvinylidene chloride and chlorinated natural rubber, wherein theratio of the component (A-1) to the component (A-2) is about 1.2 : 1 to1.8 : 1 by weight, 2 to 15 parts by weight of (B) a plasticizer selectedfrom the group consisting of phthalates, adipates, alkylphosphates andchlorinated paraffins and 2 to 20 parts by weight of (C) a wax having 30to 80 carbon atoms and melting at 60 to 120°C, said wax being selectedfrom the group consisting of animal wax, vegetable wax, petroleumparaffin wax, petrolatum and microcrystalline wax.
 2. The compositionaccording to claim 1, which further comprises carbon fluoride.
 3. Thecomposition according to claim 1, wherein the component (A-1) is achlorine-containing rubber and the component (A-2) is achlorine-containing rubber.
 4. The composition according to claim 1,wherein the component (A-1) or the component (A-2) is the one having achlorination rate of not less than about 60 %.
 5. The compositionaccording to claim 1, wherein the component (B) is a chlorinatedparaffin having a chlorination rate of about 40 to 80 % and a molecularweight of not less than
 1000. 6. The composition according to claim 1,wherein the component (C) is the one having 30 to 80 carbon atoms and amelting point of 60° to 120°C.
 7. The composition according to claim 6,wherein the component (C) is a crude type microcrystalline wax.
 8. Thecomposition according to claim 6, wherein the component (C) is a hardtype microcrystalline wax.
 9. The composition according to claim 6,wherein the component (C) is the one having 40 to 60 carbon atoms and amelting point of 70° to 90°C.
 10. The composition according to claim 9,wherein the component (C) is a plastic type microcrystalline wax. 11.The composition according to claim 1, which further comprises a solvent.12. The composition according to claim 11, wherein the solvent is amember selected from the group consisting of alcohols, esters, ethers,ketones, hydrocarbons and halogenated hydrocarbons.
 13. The compositionaccording to claim 11, wherein the solvent is employed in an amount thatthe solid content in the composition is made 1 to 60 % by weight. 14.The composition according to claim 13, wherein the solid content is made10 to 40 % by weight.